Apparatus for heat transfer



NOV. 1941- H. A. B UR GGRABE HA2. APPARATUS FOR HEAT TRANSFER FiledApril 9, 1938 2 Sheets-Sheet 1 INVENTORs.

Jam 4.

, ATTORNEY:

Nov. H. A. BURGGRABE ET AL 2,263,068

' APPARATUS FOR HEAT TRANSFER Filed April 9, 1938 2 Sheets-Sheet 2Patented Nov. 18, 1941 UNITED STATES PATENT OFFICE APE'ARATUS ron rma'rTRANSFER Henry A. Burggrabe and William K. Body, De-

troit, Mich,

ration, Chicago, 111.,

This invention relates to a method of and apparatus for heat transferand, as illustrated in the drawings, has particular reference to the artof refrigeration.

The invention as illustrated in the embodiment selected for purposes ofillustration contemplates a refrigerating system including a compressor,a condenser adapted to receive refrigerant discharged by the compressor,a motor for driving said compressor and means for conducting refrigerantfrom the condenser in heat exchange relationship with the motor fordissipating heat therefrom. V

A principal object of the invention is to provide a new and improvedmethod of and apparatus for heat transfer, particularly inconnection-with a refrigerating system.

Another object of the invention is to provide a new and improved methodof and apparatus for dissipating heat from a refrigerating system andfrom the source of energy which effects the operation of such system.

Another object of the invention a new and improved method of andapparatus for dissipating heat from an electric motor which operates todrive a compressor of a refrigerating system.

Another object of the invention is to provide a new and improved methodof and apparatus for heat transfer useful in refrigerating systems ofthe compressor type whereby the efliciency of the heat dissipatingelements and parts of the system is increased and the possible capacityof the system as a whole is increased.

Another object of the invention is to provide a new and improvedrefrigerating system which includes a sealed unit construction withmeans for efllcientlydissipating heat from the sealed unit. 7

Another object of the invention is to provide a new and improvedconstruction for refrigeratingsystems of the sealed unit type, which ischeaper in construction and more efficient in operation thanrefrigerating systems of the sealed unit type 'now commonly employed.

. Other objects and advantages of the invention will be apparent from aconsideration of the following specification. taken the accompanyindrawings two sheets and wherein Fig. 1 is an illustration of arefrigerating systern embodyin the invention? a Fig. 2 is a plan view ofthe condensingunit art of the refrigerating apparatus illustrated inFig. 1; 1

Fig. 3 is an enlarged elevational view of the of which there are inconiunction with assignors to Borg-Warner Corpoa corporation of IllinoisApplication April 9,, 1938, Serial No. 201,040 1 Claim. (01. 62-115)condensing unit part of the system illustrated in is to provide 4 Fig.l; and

Fig. i is a vertical sectional view of the sealed unit or motorcompressor unit such as appears from a view taken in a plane on the line4-4 of Fig. 2 looking in the direction of the arrows.

Referring now to Fig. 1 of the drawings, there is shown a refrigeratingsystem of the compressor, condenser, expander type and which includes asealed motor compressor unit ID, a condenser l2, an'evaporator l4 and athermostatic control switch 16 arranged in the motor circuit I8 andhaving a thermal element 20 associated with the evaporator I4 so thatthe motor compressor unit I!) will operate to supply refrigerant to theevaporator l4 in accordance with the preselected temperaturerequirements thereof. The evaporator i4 is illustrated as being arrangedwithin a heat insulated compartment 2|, and a liquid line 22 connectedwith the liquid receiver 24 of the condensing unit is adapted to supplyliquid refrigerant to the evaporator under the control of some suitablecontrol, such as a low side or high side float control, and a suctionline 26 is connected to the evaporator 14 for returning vaporousrefrigerant therefrom to the motor I indicated generally at 32 and whichcompressor is driven by the motor 30. Vaporous refrigerant from theevaporator is delivered by the suction line 26 to the intake side of thecompressor 32 and such refrigerant after being compressed by thecompressor is dischargedinto the space withln'the shell 28 of the motorcompressor unit l0.

From the shell 28 refrigerant under the discharge pressure of thecompressor 32 is conducted by the conduit 34 I 'The condenser I!generally comprises a pair of side frame members 16 which form a supportfor the finned coils 38 and which finned coils are adapted to be exposedto" air so as to dissipate heat from the refrigerant within the coils.The condenser l2 consists of two parts which may be called a primarycondenser 40 and a secondary condenser 42. V

V The vaporous refrigerant from the motor compressor unit In isconducted by the conduit 34 to one end 44 of the primary condenser 40and the other end 48 of the primary condenser is connected by a conduit48 to an annular Jacket or to the condenser l2.

chamber so disposed around the motor a of the motor compressor unit It.A conduit 52 is provided for conducting refrigerant from the jacket and29 which are welded together so as to form a gas-tight shell in whichthe motor 30 and the compressor 32. are arranged. The conduit 28 whichconducts refrigerant to the compressor 32 and the conduit 34 whichconducts refrigerant from within the casing 28 to the condenser passesthrough the walls of the casing 28 and are sealed was to prevent loss ofgas therearound. Leads 60 may be mounted in the top of the casing 28 bymeans of which current may be supplied to the windings of the motor 30.The motor 30 may be a split-phase motor having starting and runningwindings, in which event three leads, as illustrated in Fig. 2, would berequired. The compressor 32 and the motor 30, which are directlyconnected, may be supported within the casing 28 by means of a' sleeve62 press-fitted into the casing 28 and the walls of the casing 28opposite the sleeve 52 may be bulged outwardly, as illustrated, to formthe jacket 50. The motor compressor unit is further described andclaimed in the copending application of John C. Buchanan et al., filedMay 25, 1938, Serial No. 209,914, for

Refrigeration, and reference may be had to such application for furtherdetails of'the construction and operation of the motor compressor unitper se. The unit It may be provided with several brackets 64 by means ofwhich the unit Ill can be suspended from brackets 68 carried by a frame68 mounted on the condenser, springs being employed for suspending theunit ill from the brackets 66 so as to, prevent the transmission ofvibration from the unit It to the condenser I2. The conduits connectingthe unit In with the condenser l2 and the evaporator l4 may be formed'of copper tubing and be sufficiently flexible to prevent thetransmission of vibration by means of the conduits to other parts of thesystem. The frame 68 may comprise several pieces of strip metal bent andsecured together and bolted to the side frame members 36 of the 0011-.denser so that the motor compressor unit will be supported in a verticalposition above the condenser as illustrated. The receiver 24 maylikewise, as illustrated, be carried by a part of the frame 68.

The first stage or pass-40 of the condenser 52 may be of such capacitythat the conduit 48 will deliver to the jacket 50 approximately justsuflicient liquid refrigerant So as to keep the temperature of the motor30 within a desired workin range under the various temperature andpressure conditions to which the system is subjected. In other words,the first pass 40 of the condenser may be of such capacity that therefrigerant leaving the jacket through the conduit 52 will all be in avaporous state and will be delivered to the second pass or stage 42 ofthe condenser. This second stage or pass of the condenser is ofsufficient capacity to liquify all of the refrigerant under the variousconditions of temperature and pressure for which the system has beendesigned. By increasing or decreasing the capacity of the first pass 40of the condenser, the temperature at which the motor operates may bevaried. It is possible with this type of construction to ratheraccurately control the temperature of the motor under its variousconditions of operation. The liquid refrigerant delivered by the conduit48 to the jacket 50 functions to absorb heat from the motor windings, asa result whereof temperature of the motor is reduced or regulated andthis motor heat which is added to the liquid refrigerant will vaporizethe same and will be dissipated from the refrigerant in the second passof the condenser.

This system of dissipating heat from the motor compressor unit It!serves to increase the efllciency of the system as a whole, and actuallyincreases the capacity of the system. This method of dissipating heatfrom the motor compressor unit also is somewhat less expensive than finswhich have heretofore been employed on motor compressor units. Ifdesired the size of the jacket 50 maybe increased or decreased forchanging the rate at which heat may be dissipated from the motorcompressor unit Ill.

The particular details of construction of the various pieces ofapparatus illustrated are not particularly important to the inventionand it is to be understood that various changes in design, size, shapeand form may-be made in the system and the parts thereof withoutdeparting from the scope of the invention as defined in the followingclaim.

While the invention has been described with some detail, it is to beunderstood that the description is for the purpose of illustration onlyand is not definitive of the limits of the inventive idea. The right isreserved to make such changes in the details of construction andarrangement of parts as will fall within the purview of the attachedclaim.

We claim:

A-refrigerating apparatus including a sealed casing having a motorsection and a compressor section, said motor section being pressed outat the side thereof to define a channel, an annular sleeve pressed intosaid motor section and forming with said channel an annular passagebetween said sleeve and said motor section, motor windings supportedwithin said annular sleeve, 9. frame connected with the bottom of saidannular sleeve, a compressor unit supported upon said frameindependently of the compressor section of said sealed casing andarranged to be driven by said motor, said annular passage being arrangedfor circulation therethrough of a refrigerant for effecting indirectheat exchange with said motor for removing heat therefrom.

HENRY A. BURGGRABE. WILLIAM K. BODY.

